Metallized, Oriented, and Thin LLDPE Films

Abstract

This disclosure provides compositions and methods for an oriented film that may include a core layer consisting essentially of biaxially oriented linear low-density polyethylene, wherein the core layer has a first side and a second side. Further, the film may include a first sealant layer consisting essentially of biaxially oriented linear low-density polyethylene on the first side, and a second sealant layer consisting essentially of biaxially oriented linear low-density polyethylene on the first side, wherein the linear low-density polyethylenes in each of the film's layers may be of more than one type/grade, have the same or different densities, or both. Further still, the film is 30 μm or less in thickness, has a water-vapor transmission rate of ≤1 g/m 2 /d at 38° C. and 90% relative humidity, and has an oxygen transmission rate of ≤100 cm 3 /m 2 /d at 23° C. and 0% relative humidity.

1 . A three-layered film comprising:
 a core layer consisting of biaxially oriented linear low-density polyethylene, wherein the core layer has a first side and a second side;   a sealant layer consists of maleic-anhydride-grafted polyethylenes, and optionally, additives, wherein the sealant layer is located directly on the first side, and, optionally, having a primer between the sealant layer and the first side; and   a metallizable layer consists of biaxially oriented linear low-density polyethylenes, and, optionally, additives, wherein the metallizable layer is located directly on the second side, and optionally having a primer between the metallizable layer and the second side,   wherein the linear low-density polyethylene in the sealant layer has a lower melting peak than the linear low-density polyethylene in the core layer,   wherein the three-layered film is 30 μm or less in thickness, has a water-vapor transmission rate of ≤1 g/m 2 /d at 38° C. and 90% relative humidity, and has an oxygen transmission rate of ≤100 cm 3 /m 2 /d at 23° C. and 0% relative humidity,   wherein an exterior surface of the three-layered film is flame-treated and plasma-treated.   
     
     
         2 . The three-layered film of  claim 1 , further comprising a metal layer applied to the exterior surface of the three-layered film. 
     
     
         3 . The three-layered film of  claim 1 , wherein the three-layered film further comprises one or more primers between the between the sealant layer and the first side and/or between the metallizable layer and the second side. 
     
     
         4 . The three-layered film of  claim 1 , wherein the sealant layer consists of the maleic-anhydride-grafted polyethylenes and at least one of the additives. 
     
     
         5 . The three-layered film of  claim 1 , wherein the sealant layer consists of the maleic-anhydride-grafted polyethylenes and at least two of the additives. 
     
     
         6 . A method comprising extruding, casting or blowing the core layer, the first sealant layer and the second sealant layer of  claim 1 , and orienting, subsequent thereto, wherein the film is 30 μm or less in thickness, has a water-vapor transmission rate of ≤1 g/m 2 /d at 38° C. and 90% relative humidity, and has an oxygen transmission rate of ≤100 cm 3 /m 2 /d at 23° C. and 0% relative humidity. 
     
     
         7 . A three-layered film comprising:
 a core layer consisting of biaxially oriented linear low-density polyethylene, and optionally silica-based substance(s) consisting of silicates, polymethyl methacrylate, and cross-linked polysiloxanes, wherein the core layer has a first side and a second side;   a sealant layer comprising maleic-anhydride grafted polyethylene located directly on the first side, and, optionally, having a primer between the sealant layer and the first side; and   a metallizable layer consisting of biaxially oriented linear low-density polyethylene, silica-based substance(s) consisting of silicates, polymethyl methacrylate, and cross-linked polysiloxanes, and optionally additives, wherein the metallizable layer is located directly on the second side, save an optional primer between the metallizable layer and the second side,   wherein the polyethylene in the sealant layer has a lower melting peak than the linear low-density polyethylene in the core layer,   wherein the three-layered film is 30 μm or less in thickness, has a water-vapor transmission rate of ≤0.3 g/m 2 /d at 38° C. and 90% relative humidity, and has an oxygen transmission rate of ≤75 cm 3 /m 2 /d at 23° C. and 0% relative humidity,   wherein an exterior surface of the three-layered film is flame-treated and plasma-treated.   
     
     
         8 . The three-layered film of  claim 7 , wherein the sealant layer consists of maleic-anhydride grafted polyethylene. 
     
     
         9 . The three-layered film of  claim 7 , further comprising a metal layer applied to the three-layered film. 
     
     
         10 . The three-layered film of  claim 7 , wherein the cross-linked polysiloxanes are Tosperal™ products commercially available from Momentive Performance Materials, Inc. 
     
     
         11 . The three-layered film of  claim 1 , wherein both exterior surfaces of the three-layered film are flame-treated and plasma-treated. 
     
     
         12 . The three-layered film of  claim 1 , further comprising a metal layer on each of the exterior surfaces of the three-layered film. 
     
     
         13 . The three-layered film of  claim 12 , further comprising a laminating layer on the metal layer on at least one of the exterior surfaces of the three-layered film. 
     
     
         14 . The three-layered film of  claim 1 , wherein the three-layered film does not comprise the additives for optional inclusion in the sealant layer. 
     
     
         15 . The three-layered film of  claim 1 , wherein the three-layered film does not comprise the additives for optional inclusion in the metallizable layer. 
     
     
         16 . The three-layered film of  claim 7 , wherein the three-layered film does not comprise the additives for optional inclusion in the metallizable layer.